Photo-electro-striction in halide perovskite semiconductors

MAPbI3, MAPbBr3, and CsPbBr3 are excellent halide perovskite semiconductors with super long carrier diffusion length, long minority carrier lifetime, and large light absorption coefficient. Compared with the small intrinsic electrostriction, photocarriers induce a large photostriction in the surface layer. Furthermore, an electric field can efficiently separate the light excited electron–hole pairs, enhance photocarriers diffusion, and finally increase the crystal expansion, i.e., photo-electro-striction. For each crystal under 30 V/mm and in light with 450 nm wavelength and 840 mW/cm2, the photo-electro-striction is over four times of the pure electrostriction and is larger than the sum of photostriction and electrostriction. Most importantly, MAPbI3 single crystal shows a large photostriction of ∼0.35% and the photo-electro-striction of ∼0.64%. This work proves a very large photo-electro-striction as a result of the strong coupling among photocarriers, electric fields, and crystal lattices, which is important to develop semiconductor devices.